Autoimmune pancreatitis type 2

Abstract

Purpose of review: Type 2 autoimmune pancreatitis (AIP) is a rare inflammatory disease of the pancreas. Very few data have been published on this particular subtype, which differs from the 'classical' IgG4-related type 1 AIP in terms of pathological features, epidemiology and risk of relapse. The aim of the current review is to summarize the available literature, suggesting a diagnostic and therapeutic approach to this disease.

Recent findings: Based on the International Consensus Diagnostic Criteria, to achieve a 'definitive' diagnosis of type 2 AIP, histology is required. If a definitive histological diagnosis is lacking (not-performed or inconclusive), concomitant presence of inflammatory bowel disease (IBD) and effective response to steroids are needed for a 'probable' diagnosis of type 2 AIP.

Summary: Type 2 AIP is a selective pancreatic disease, without association to other organ involvement. The lack of validated serological markers makes the diagnosis challenging in clinical practice, particularly in focal forms. A careful evaluation of the clinical profile (especially of a concomitant IBD), associated with an accurate imaging, might help in clinical practice to suspect type 2 AIP. Response to steroids is crucial to achieve diagnosis in patients without a diagnostic histology.